I. Field of the Invention
The present invention relates generally to the part fixture presentation as used in robotic systems and work cells and specifically to a modular design of the positioning robotic system that allows changes from one type of positioning module to another positioning module that can be selected from a variety of modules and can be used in conjunction with a stationary base or a drive unit that adapts without having to switch the control architecture. A positioning robotic system is originally assembled with a specific positioning device, drive and control module. When the use of the system needs to be changed to accommodate a change in weld locations of a new product because of a change in the diameter, length, width or weight of the fixture and part combination, the positioning device system can be changed to a different system configuration without having to necessarily change the entire system. Instead, only individual components need be changed.
II. Problems in the Art
Many manufacturing processes have become automated. Typically, robots consist of a single mechanical arm that has a limited number of axis about which the arm can move or rotate. The robot arm has a tool, such as a welder, attached to the end of the arm. To provide better robot access to a part fixture combination, modern assembly lines also provide work tables, or positioning modules that hold fixtures and parts, that can be moved to position a product being worked on by the robotic arm within the reach of the arm.
There are a great variety of positioning modules that can position material within the reach of a robot. One such module is a turntable. A turntable is essentially a flat round surface that rotates about an axis. The turntable typically enables the robotic arm to work on parts on one portion of the circular surface while the other portion of the table is loaded and unloaded. The table is rotated about an exchange axis to more safely separate the operator from the robotic arms' movements. The turntable is ideal for situations in which the parts do not need to be repositioned while being processed.
Another positioning module design is the H-frame. The H-frame module rotates about an axis also, but instead of having a flat surface to mount fixtures and parts to, it has two sets of arms that products are mounted between. The addition of arms allows for the system to have two axis of rotation to better provide for the robot to work.
Another style of positioning module is termed a Ferris wheel frame. A Ferris wheel frame is essentially a rectangular shaped flat surface that pivots around an axis that extends along the length of the surface. Arms are mounted perpendicular to the planar surface of the Ferris wheel. Much like the H-frame, products or fixtures (devices used to hold smaller sized products) are suspended between the arms.
Modern assembly lines, work cells and factories typically consist of a mixture of work stations that require different types of positioning devices because of the unique processing needs of the part. Today's work station is set up and built around tool turning diameters and length, and are designed to function in a specific way. If the part being produced requires a change in the part fixture, then the entire work station and positioning module may need to be replaced or reconfigured.
When a manufacturing plant, assembly line or work cell is retooled to manufacture a new product there is a significant period of down time where the facility does not produce any product. Because of the complexity of the tools, changeover in a highly automated process can take even longer than more traditional assembly plants. Most often, robotic automation fixtures and part combinations come with fixed components that are only common to their tool fixture and part combination.
Several problems arise from this standardization by tool fixture and part combination. Because each tool fixture and part combination is unique and has unique components, a change in tool fixture and part combination can result in the need to buy new capital equipment because the existing station cannot be adjusted for positioning the new tool fixture or part combination because length or diameter changes. The change in systems often causes the utilities to need to be rerouted, which then cause additional down time. The more change overtime, the more money is lost. Additionally, having to replace an entire system is much more expensive than replacing a single component of a system.
It is therefore a primary objective of the present invention to provide a design for a modular system comprised of components that can easily be interchanged and adjusted.
A further feature of the present invention is to provide a modular positioning robotic system that has a control architecture which can be adjusted and used for any selected positioning module/system type utilized in a standard robotic system family.
A further feature of the present invention is to provide a modular system that is easily networked.
Yet another feature of the present invention is to provide a control module that interfaces with a robot controller wherein the robotic controller performs the logical functions.
A still further feature of the present invention is to provide a controller module that interfaces with and controls a drive module.
Another feature of the present invention is to provide a modular positioning robotic system that utilizes an adjustable H-frame positioning module that can add and/or delete an exchange axis drive module or turntable.
Yet another feature of the present invention is to provide a modular positioning robotic system that utilizes a turntable positioning module that can be interchanged with an adjustable H-frame.
Yet another feature of the present invention is to provide a modular positioning robotic system that utilizes an adjustable tool length and width Ferris wheel positioning module.
Yet another feature of the present invention is that the H-frame, turntable and Ferris wheel positioning modules are interchangeable.
A still further feature of the present invention is that the modular positioning system integrates with one or more robots.
A modular positioning robotic system and a method of accomplishing these and other features will become apparent from the following description of the invention.